MULTIPLE PERSONALITY DISORDER
The central feature of the extremely rare multiple-personality
disorder is the existence of two or more apparently distinct
personalities in one individual. Each of the personalities is
associated with unique ways of thinking, behaving, and expressing
emotion. In some cases the multiple personalities are fully
developed in the sense that they are associated with distinctly
different types of identities and have different memories for past
events. In other cases, characteristics of the personalities
overlap so that they share some traits and memories. Either way,
a person with the disorder responds differently on psychological
tests, and may even demonstrate different patterns of brain
activity, for each personality. The transition from one
personality to another typically is abrupt and is precipitated by
a stressful experience or environmental cue.
Patients with multiple-personality disorder vary in the extent
to which they are aware of their condition. Some are unaware that
they manifest dramatic changes in personality, whereas others are
conscious of the fact that they show distinct personalities. The
extent of the functional impairment in these patients varies from
mild to severe. The cause of the disorder is as yet unknown.
PSYCHOTHERAPY is the most common form of treatment for multiple-
Studies of multiple-personality disorder report that it occurs
from three to nine times more frequently in females than in males.
Onset of the disorder often occurs in childhood, and in almost all
cases the disorder is preceded by some form of abuse or other
traumatic event. Confirmed cases of multiple-personality disorder
number only in the hundreds. Recent research has suggested,
however, that multiple-personality disorder may occur more often
than previously thought.
Bibliography: Bootzin, R. A., and Acocella, J. R., Abnormal
Psychology, 5th ed. (1988); Confer, W. N., and Ables, B. S.,
Multiple Personality (1983); Endler, N. S., and Hunt, J. M.,
Personality and the Behavior Disorders, 2 vols., rev. ed. (1984).